Published on April 30th, 2012 | by Glenn Meyers3
Scientists Report on Night-Warming Effect over Large Texas Wind Farms
According to a recent press release from the National Science Foundation, large wind farms in certain areas in of this country appear to affect local land surface temperatures.
The news is based on a paper published today in the journal Nature Climate Change. Liming Zhou, an atmospheric scientist at the State University of New York (SUNY) Albany, oversaw the study.
“This study indicates that land surface temperatures have warmed in the vicinity of large wind farms in west-central Texas, especially at night,” says Anjuli Bamzai, program director in the National Science Foundation’s (NSF) Division of Atmospheric and Geospace Sciences, which funded the wind farm research. “The observations and analyses are for a relatively short period, but raise important issues that deserve attention as we move toward an era of rapid growth in wind farms in our quest for alternate energy sources.”
Notably, as American Wind Energy Association (AWEA) CEO Denise Bode states: “This study says nothing about wind energy and global climate, and casts no doubt on all the other studies that find wind power is one of the best ways to address climate change. The study merely examined the effect of local air mixing at the site of a wind farm, which has nothing to do with climate because no heat or heat-trapping gases are being added to the atmosphere.”
Nonetheless, there are things to be learned and more research to be done about the micro-climate impacts of wind turbines. Previously, a study from Iowa State University actually found that wind turbines benefit crops, because of the effects they have on air circulation.
“We need to better understand the system with observations, and better describe and model the complex processes involved, to predict how wind farms may affect future weather and climate,” said Zhou.
To understand the potential impact of wind farms on local weather and climate, Zhou’s team analyzed satellite-derived land surface temperatures from regions around large wind farms in Texas for the period 2003-2011. The researchers found a nighttime warming effect over wind farms of up to 0.72 degrees Celsius per decade over the nine-year-period in which data were collected.
A co-author of the paper, Somnath Baidya Roy of the University of Illinois at Urbana-Champaign, contends the warming effect is most likely caused by the turbulence in turbine wakes acting like fans to pull down warmer near-surface air from higher altitudes at night.
“The estimated warming trends only apply to the study region and to the study period, and thus should not be interpolated into other regions, globally or over longer periods,” Zhou said. “For a given wind farm, once there are no new wind turbines added, the warming effect may reach a stable level.”
Source: AAAS EurekAlert
Photo credit: Lubbock County, Texas